Showing papers on "Shielding gas published in 1972"

Welding material for super low temperature steels

Abstract: This invention provides a welding material for super low temperature steels which comprises not more than 0.2% carbon, 5 - 12% manganese, not more than 30% chromium, 4 - 8% niobium, 22% iron and not more than 1.5% silicon, the balance being substantially nickel, and which can give excellent strength and impact value to the weld zone. In one embodiment, the welding material is an integral body composed of a metal-forming material and a flux of lime or lime-titania in which the metal forming components are within the above range.

Lead battery welding method and apparatus

Abstract: A welding method for fusing lead components together in a lead-containing electrochemical cell is disclosed together with apparatus for carrying out the method. The method includes forming an ingot-like mold around the lead components to be welded, the walls of the mold being comprised of a material having a high softening point, good thermal conductivity and arc-erosion resistance. Arc welding of the components utilizing an inert-gas-shield nonconsumable electrode, e.g. tungsten, is accomplished by passing the electrode over a weldable surface formed by the lead components in an oscillating path at a controlled speed and welding current to permit the lead components to melt and flow into the ingot-like mold while simultaneously controlling heat transfer through the adjacent mold walls. The resultant weld is of low internal impedance and is relatively thick for increased oxidation and corrosion resistance during operation of the battery.

Method for heating corrosive gases with arc heater

Abstract: Corrosive gases, such as air, oxygen, carbon monoxide and carbon dioxide, are heated in an electric arc gas heater by passing the gas to be heated through the arc heater and in contact with an electric arc established between the cathode and anode electrodes thereof. At least one electrode contains less than about 0.0005 volume percent of voids of at least 0.019 inch in any dimension in the area of the electrode eroded by arc operation. Ultrasonic testing is used to determine the void content of the electrodes.

Gas shielded core wire electrode

Abstract: A core wire electrode for use with a shielding gas, particularly in out-of-position welding, said electrode having a core material containing magnesium and/or magnesium aluminum alloys

Magnetic control of gas tungsten-arc welding process

Abstract: The possibility of increasing the welding speed in the gas tungsten-arc welding process by using external magnetic fields was investigated. The effects of a constant, transverse magnetic field applied to the arc were studied. Nine percent nickel steel and aluminum alloys types 2021, 6061 and 5454 were the materials used for this investigation. Type 4043 aluminum was used as a filler wire for aluminum and Inconel 625 for the 9% Ni steel weld specimens. Most of the welds were made without the addition of filler metal. All the weld specimens were of bead on plate type. By applying transverse magnetic fields, the maximum welding speed at which undercut-free welds could be obtained was increased considerably. The 9% Ni steel responded exceptionally well to the applied magnetic fields. The magnetic field strength required to produce a satisfactory bead appearance varied with current and travel speed. The arc deflection is consistent with the motor rule. It is suggested that the electromagnetic pumping action of the interacting self and applied magnetic fields produces an improvement in bead appearance.

Method for underwater arc welding

Abstract: According to the method of this invention water is kept away from the arc in underwater arc welding by means of a gas under a pressure greater than that of the water and, preferably, the wire feeding unit, welding gun, and electrode wire of the gas shielded, metal arc welding apparatus to be used underwater are enclosed in air-tight and water-tight containers. The containers and conduits are then internally pressurized with a shield gas to prevent the entry of water. The welding gun or at least its nozzle is inserted through a flexible sealed orifice in a small local housing chamber having a second opening. This second opening is placed against the work-piece to be welded. Shielding gas is supplied to the housing chamber at a pressure greater than the surrounding water to force water from the chamber and permit welding to take place in a region free of water.

Stability of a gas-liquid interface and its relation to weld pool stability

Abstract: In the present work the results of a theoretical analysis of the interfacial stability of a gas jet impinging on a free liquid surface are used to study the stability of weld pools. Use of experimental observations on the plasma flow inside high-current arcs allows a critical arc current, for which the weld pool becomes unstable, to be calculated. This critical current depends upon the surface tension between molten metal and arc gas, the geometry of the cathode, and the difference in density between molten metal and arc gas. Observations on tungsten-inert-gas welding support the theory.

Method of tungsten inert gas welding electronic components and burning away contaminants

Abstract: A method and apparatus wherein linear metallic elements such as copper wire leads are welded to workpieces, such as terminal lugs of electrical and electronic components. An electric arc welding method is used to produce an electrical or electronic component with copper wire leads rigidly and reliably attached, without requiring prior cleaning of the terminal lugs of the component. In the welding step a surplus of heat energy greater than that necessary to melt and coalesce the weld material is applied to the welding zone in order to burn away contaminents at the area to be welded.

An automatic narrow-gap butt-joint overhead-position arc-welding method

Abstract: 1294451 Welding by fusion KAWASAKI JUKOGYO KK 12 Nov 1969 55342/69 Heading B3R In overhead position, narrow groove, MIG, arc butt welding, at least one set. of three electrode wire nozzles are used, two of the nozzles 13, 13 1 being positioned side-by-side and directing their electrode wires towards opposite workpiece surfaces, and the third nozzle 15 being positioned centrally and following the side-by-side pair. The side-by-side electrodes are preferably at reverse polarity (for arc stability) and the single electrode at straight or reverse polarity. As shown in Fig. 3, a series of sets of three nozzles are provided in succesion along the joint to produce a plurality of layers 25-33 during a or each single pass. To provide for successive passes in opposite directions, a pair of electrodes or, as shown, a single electrode is arranged at both ends of the series, current being cut off respectively from a hindmost pair of electrodes or a leading single electrode. Shielding gas examples are A, He, CO 2 , O 2 or a mixture thereof.

Apparatus for arc welding

Abstract: There is described herein an apparatus which facilitates electric arc welding either underwater or under adverse atmospheric conditions. This apparatus includes a housing chamber having three primary apertures therein. The first and second apertures are disposed oppositely of each other. A piston-like, hollow insert is adapted to be coaxially positioned in the first aperture. A transparent viewing member is disposed in the first aperture and held in place by the insert. A contact gasket is removably secured to the periphery of the second aperture to provide a seal between the work piece to be welded and the housing. A flexible sealing gasket is secured over the third aperture and is adapted to sealingly receive the welding gun. Finally, there is a means for introducing a shielding gas into the chamber to maintain it substantially free of the fluids from the surrounding environment during the welding operation. In underwater applications the welding electrode is held by a welding gun having a hollow guide tube which supports the welding electrode. A gas valve in the welding gun permits the entry of a gas under pressure to be introduced in the annular space within the guide tube about the welding electrode to permit a jet of gas to be used to clear the work area either when initially started or at other times during the welding process. Similarly, the welding current control switch is adapted to be surrounded by pressurized shielding gas to maintain it substantially water-free and thereby avert short circuits. A rocker arm mechanism is utilized to actuate the gas valve and the welding control switch such that either but not both may be actuated at a time. This is necessary to prevent the electrical arc from being blown out by the sharp blast of cleaning gas. The gun itself is formed of a solid member having various channels formed therein to provide for the necessary gas conduits and electrical wiring. Suitable end caps are placed over either end of the gun member to provide a water seal and to strengthen the gun.

Electrode for arc welding

Abstract: An electrode for arc welding, comprising a core based on iron with alloying additives of chromium, nickel and titanium, and a coating consisting of fluorite, rutile concentrate, iron powder, chromium and mica. In addition to the above components, said coating also contains magnesite, ferrotitanium and ferroniobium that ensure high plasticity and resilience to the deposited metal, the latter thus being resistant to the formation of pores and hot cracks.

Improved welding machine

Abstract: 1,262,634. Welding by fusion. RICHARDSONS WESTGARTH & CO. Ltd. 5 Feb., 1969 [8 Feb., 1968], No. 6343/68. Heading B3R. A welding machine comprises an elongate probe-like arm 11a mounted for 'movement along its own axis, and a welding head 14 carried at one end of the arm, the head comprising a flat-sided member provided with guide means for engagement with the work to guide the arm during welding. The arm 11a, which is mounted so as to permit limited lateral movement thereof, is axially movable between rollers 10 by a rack-and-pinion mechanism. The carriage 12 supporting the arm is adjustable vertically on pillar 13 which may be angularly adjustable on base 25. The welding head 14 comprises a block assembly 16 provided with a cut-away 19 accommodating one or a pair of arcuate wire guide nozzles 26 which are replaceable. The nozzles diverge slightly downwardly. The block assembly 16 has front and rear guides 18, 17 and may also have a resilient top guide 23. The block assembly 16 is provided with cooling water passages, and apertures for feeding a shielding gas into the cut-away 19. Welding wires 21 may be driven by a single feeder supplied from separate insulated supply rolls 15. The block assembly 16 may be replaced by two separate blocks spring-loaded apart whereby two seams having limited divergence or convergence may be welded simultaneously, one wire being fed to each block. In use, the head is introduced into a hollow workpiece with a restricted entry, e.g. a box section, and the sides and bottom of the workpiece co-operate with the cut-away 19 to form a chamber which retains shielding gas adjacent the weld. Where a weld is to be made in, e.g. a deep Vee-groove, a single weld only being required, only one wire feed nozzle is provided the tip of which has opposed flats whereby the tip can be approached close to the work. Submerged-arc and M.I.G. welding are referred to, it being stated that in bigger machines a cored wire can be used in a flux-submerged process. Where twin arcs are used two power supplies with linked controls are provided.

Arc welding torches for tube plate welding

Abstract: The torch described herein is for making internal bore welds. It has a stem carrying a non-consumable electrode and a body from which the stem projects. To make a weld, the stem is inserted into a bore so that the electrode is positioned near the join to be welded and the electrode is orbited around the join while an arc is maintained to make the weld. The stem has a core of high heat conductivity which is in contact with both the electrode and a heat sink block in the torch body. Provision is also made for the passage of inert shielding gas from the body and along the stem to the region of the electrode, this core and/or block having an extended surface area over which the inert shielding gas is arranged to pass so as to assist in cooling these and consequently the electrode.

Travelling arc-welding apparatus

Abstract: 1285285 Welding by fusion CRC-CROSE INTERNATIONAL Inc 4 June 1970 [4 June 1969] 26984/70 Heading B3R A MIG butt welding apparatus comprises a carriage movable along a guide track capable of being secured adjacent the line of the joint to be welded and a welding head movable transversely of the joint. The apparatus is particularly for use in butt welding of pipes but may also be used for butt welding flat plates. In Figs. 1, 3 a transversely oscillatable and adjustable welding head 61 is supported on a carriage 21, on the one hand via a stiffly resilient coiled metal spring wire guide 104 tending to centre, but permitting transverse deflection of, the head, and on the other hand via a bracket 57 pivoted on the carriage. The bracket 57 has adjustably slidable thereon a plate 140 having arms 134, 136 provided with cam followers 137 selectively engageable, by means of knobcontrolled eccentric 164, with cam grooves disposed on opposite sides of a cam 130, each cam providing a different amplitude of head oscillation. The cam 130 is rotatable, via a gear reducer (128), by a motor 126 which is connected to the carriage by a screw 120 adjustment of which varies the general transverse position of the head. Consumable electrode wire from a reel 72 is taken through flexible and semiflexible tubes 60, 102, motor-driven and spring- pressed feed rollers (82, 84) and the wire guide 104. The carriage has grooved rollers 23, 25 engaging a flexible guide track 27 held by tension on the workpiece surface. One or more carriages may be used on tracks 27, 33 on either side of the joint. The carriage, controlled from a box 39, is propelled by one or more of the grooved rollers driven by an electric motor 43. A connection 70 to the welding heads supplies welding current and shielding gas (e.g. nitrogen, argon). With neither cam follower 137 engaging a cam groove, the head is held by the guide tube and does not oscillate. In Fig. 10, a pivoted welding head supporting bracket 57a is axially movable, against a spring 300, by a face cam 130b to provide for longitudinal reciprocation of the head. Transverse oscillation may be added to the longitudinal oscillation to achieve more complex weaving patterns. In Fig. 13 (not shown), the reciprocation cam is double acting so that the spring 300 may be dispensed with. In Figs. 6-8 (not shown), a screw directly transversely adjusts a pivoted bracket 57 supporting the welding head, no provision being made for oscillation. Welding of thick-walled pipes may comprise the following steps: (i) making an initial inner pass manually or automatically and preferably internally, (ii) making one or more rapid " hot " passes using heavy current, from the outside, to fuse into the inner pass and the workpieces, and (iii) making one or more cooler, slower, oscillated head, passes, the latter acting as a corrosion resistant cover for the corrosion susceptible austenitic conditions created by the " hot " passes. The hot pass step may be effected, using the apparatus of the invention, by making one or more vertical electrode feed passes, one or more angled passes, or a combination thereof. When making angled passes, the weld gap may be filled by alternate side corner passes, as by alternately using separate heads respectively on tracks mounted one on each side of the joint. The joint preparation may comprise, from inside to outside, a small V, a narrow land where the adjoining pipe ends actually or nearly abut, a perpendicular or nearly perpendicular wall stepped back, say 1/32-1/8 inch, in one or both pipe ends, and a wide V.

Clamping and tool device

Abstract: 1275150 Fusion welding J P PEYROT 31 Dec 1969 [31 Dec 1968] 63580/69 Headings B3B and B3R A device for clamping two cylindrical workpieces in coaxial relation and for welding, machining or checking the workpieces, comprises two pivotally related jaw members 13 1 , 14 adapted to be closed on to the workpiece by adjustable toggle clamping and release levers 16, 17, 19 Each member 13 1 , 14 is forked, the forks carrying work engaging members such as the pivotally mounted member 7, the adjustable abutment 5 and the resiliently mounted member 24 A C-shaped member 30 which carries the welding torch 28, eg, for TIG welding, or alternatively a tool or checking device, is rotatably mounted by means of a set of rollers 40 on an axially adjustable slide 43 on the clamp body member 13 and is adapted to be driven through bearing from a variable speed electric motor 61 The C-shaped member 30 is provided with grooves for winding thereon conduits for the supply of arc shielding gas, cooling water and electricity The gear transmission from the motor 61 to the C-shaped member may include a pulse generating device in the form of a small magnet mounted on one of the gears and arranged to close electrical contacts in a vacuum ampoule once for each rotation of the gear, the pulses generated being employed in connection with automatic weld control means The welding torch is held at the desired spacing from the work surface by a roller 31 maintained in contact with the workpiece by a spring 32 The device may, as shown, be hand held and the clamping jaws closed manually or for heavier work the whole device may be bench mounted The C-shaped member carrying the welding torch or tool may be disposed between the forks or to one side thereof Reference is made to the device as used alternatively for electron beam welding, plasma arc welding, ultrasonic testing, machining, polishing and brushing

A process and apparatus for the direct-current arc welding of workpieces

Abstract: 1294135 Welding by fusion UNITED KING- DOM ATOMIC ENERGY AUTHORITY 28 April 1970 [6 Feb 1969] 6554/69 Heading B3R Arc welding apparatus includes means for determining whether or not a stable arc has been established, and means for switching off the welding current if an unstable arc is found to exist after an initial period usually sufficient for the establishment of a stable arc. As shown, a variable potentiometer 7 (Fig. 3) is set to a reference voltage, say 10 V., corresponding to a stable arc. The potentiometer is connected in circuit with a reference resistor 9 and relay contact DR-1; terminals A, B of this circuit are connected across the main current conductors of the welding circuit (Fig. 1). D.C. welding current is supplied to the torch 2 from rectifier 1; the open circuit voltage may be 100 V. After striking of the arc, the voltage across a relay SR/3 between terminals A, B drops from the open circuit voltage to the arc voltage. If the arc is stable, relay SR/3 experiences a voltage drop of say 10 V. which is insufficient to maintain it energized and, as a result, a weld sequence timer is energized to thereafter control the weld cycle as is usual. If, however, the arc is unstable, relay SR/3 experiences a voltage which may fluctuate in the range 25-40 volts which maintains it energized and prevents the timer being energized. The arc voltage is supplied to terminals A, B so that where the applied voltage exceeds the reference voltage on potentiometer 7, a voltage difference across reference resistor 9 causes a relay FR/1 to be energized, opening its contacts (FR-1). (Fig. 2, not shown), to shut off the welding current. Comparison of the arc and reference voltages is delayed by a delay relay DR/1 whose contact DR-1 retains the reference circuit open for a period usually sufficient to allow a stable arc to be established. This period may be about 10 milliseconds. Thereafter contact DR-1 closes. In the event of an unstable arc being determined, the welding sequence is terminated in a few milliseconds from attempting to strike the arc, before damaging heating of the work can occur. Additionally, the commencement of welding is prevented by harmful impurities in the arc shielding gas; these impurities cause the arc voltage to be higher than under stable arc conditions. The apparatus includes a variable resistor 4 for welding current control, and a spark igniter 5. A Zener diode 12 in parallel with reference resistor 9 prevents a too large voltage input to relay control amplifier 11. Arc ignition can be assisted by providing a large capacitor across the electrode/workpiece gap.